The techniques of connecting an electrical card of a memory module, for example, to a circuit board are well known. In most cases, a card-edge connector is employed to connect the electrical card to the circuit board. There are different types of card-edge connectors for connecting various modularized electrical cards to a main circuit board of an electronic device. In general, contacts are disposed on a front edge of the electrical card and are electrically connected to terminals arranged in the card-edge connector to establish an electrical connection between the electrical card and the main circuit board.
In order to meet the needs of customers, it is necessary to continuously expand the capabilities of electronic devices. Hence, the above-described card-edge connector provided with only one slot for receiving a single electrical card is not capable of meeting customer needs. In order to solve this problem, Taiwan Patent No. M283400 provides a card-edge connector that comprises a step-shaped connector housing and two locking devices, which are all separately mounted to a circuit board. The step-shaped connector housing is constructed for receiving a front edge of two electrical cards on the same side thereof and holds the two electrical cards on another other side thereof with two isolated locking devices disposed on the circuit board.
Because the connector housing is step-shaped and the two electrical cards are staggeringly received in the card-edge connector, the space, particularly the length, required for mounting the step-shaped connector housing to the circuit board is still significantly large. Thus, it is necessary to reduce the amount of space required for card-edge connectors of this type.